Apple announced Monday afternoon at the WWDC 2013 keynote that 93% of iOS devices are already running iOS 6. 6% of users are running iOS 5, while 3% of iOS users are running another version of iOS.

Apple quickly compared the fast adoption rate of iOS software versions to the adoption rate of the latest version of Android software versions. Android has much more diversity in software versions as shown by the graph above.

OTA (over the air) updating may have had a large impact on users updating to later software much more quickly. Before OTA updating, users needed to tether their devices to a computer and launch iTunes to install an update, which was a major inconvenience at the time. Users can now update from anywhere, painlessly and quickly.

Apple notes that users being on the latest software version is important for developers because it makes it easier for developers to ensure that users get the most features out of their applications.

The reason Android is more diverse is because a lot of users cannot update to anything else. Has nothing to do with OTA. iOS would also be more diverse if Jailbreakers hadn't popped out the iOS6 JB as fast as they did.